var c=document.getElementById("zuoye");
        var ctx=c.getContext("2d");
        ctx.lineWidth = 5;
        ctx.beginPath();
        ctx.arc(70, 70, 40, 0, Math.PI * 2, false);
        ctx.stroke();
        ctx.beginPath();
        ctx.arc(160, 70, 40, 0, Math.PI * 2, false);
        ctx.stroke();
        ctx.beginPath();
        ctx.arc(250, 70, 40, 0, Math.PI * 2, false);
        ctx.stroke();
        ctx.beginPath();
        ctx.arc(110, 110, 40, 0, Math.PI * 2, false);
        ctx.stroke();
        ctx.beginPath();
        ctx.arc(200, 110, 40, 0, Math.PI * 2, false);
        ctx.stroke();
        ctx.lineWidth = 5;
        ctx.strokeStyle = "blue";
        ctx.beginPath();
        ctx.arc(70, 70, 40, 0, Math.PI * 2, false);
        ctx.stroke();
        ctx.strokeStyle = "black";
        ctx.beginPath();
        ctx.arc(160, 70, 40, 0, Math.PI * 2, false);
        ctx.stroke();
        ctx.strokeStyle = "red";
        ctx.beginPath();
        ctx.arc(250, 70, 40, 0, Math.PI * 2, false);
        ctx.stroke();
        ctx.strokeStyle = "green";
        ctx.beginPath();
        ctx.arc(110, 110, 40, 0, Math.PI * 2, false);
        ctx.stroke();
        ctx.strokeStyle = "yellow";
        ctx.beginPath();
        ctx.arc(200, 110, 40, 0, Math.PI * 2, false);
        ctx.stroke();
        ctx.strokeStyle = "blue";
        ctx.beginPath();
        ctx.arc(70, 70, 40, Math.PI * 1.9, Math.PI * 2.1, false);
        ctx.stroke();
        ctx.strokeStyle = "black";
        ctx.beginPath();
        ctx.arc(160, 70, 40, Math.PI * 0.9, Math.PI * 2.1, false);
        ctx.stroke();
        ctx.strokeStyle = "red";
        ctx.beginPath();
        ctx.arc(250, 70, 40, Math.PI * 0.9, Math.PI * 1.1, false);
        ctx.stroke();
       